Open-Irrigated Versus Non-Irrigated Catheters in SVT Ablation: Substrate-Specific Outcomes in AVRT and AVNRT

Open-irrigated catheters (OIC) provide improved cooling, deeper lesion formation, and enhanced safety during radiofrequency catheter ablation (RFCA). However, comparative evidence regarding substrate-specific outcomes with OIC versus non-irrigated catheters (NIC) for supraventricular tachycardia (SVT) remains limited. This study compared acute ablation success (AAS) and recurrence after first-time RFCA using OIC versus NIC, with particular emphasis on differential outcomes in atrioventricular re-entrant tachycardia (AVRT) and atrioventricular re-entrant tachycardia (AVNRT).

A retrospective cohort of consecutive patients undergoing first-time RFCA for AVNRT or AVRT between 2017 and 2023 was analyzed. Patients were categorized by catheter type (OIC vs. NIC). Primary outcomes were AAS and SVT recurrence during 24-month follow-up. Multivariate logistic regression and Cox proportional hazards models were used for adjusted analyses. Subgroup analyses were performed for AVNRT and AVRT.

Among 302 procedures, OIC were used in 113 (37.4%). Overall AAS was achieved in 85.4% of cases (92.0% OIC vs. 81.5% NIC; p = 0.012). Recurrence occurred in 17.9% (7.1% OIC vs. 24.3% NIC; p < 0.001). In multivariable analyses, OIC use was independently associated with higher AAS (adjusted RR 1.12; 95% CI 1.05-1.20; p = 0.001) and lower recurrence (adjusted HR 0.24; 95% CI 0.12-0.52; p < 0.001). In the AVRT subgroup, OIC use was associated with higher AAS (89.9% vs. 76.6%; p = 0.014) and lower recurrence (adjusted HR 0.25; 95% CI 0.11-0.57; p < 0.001), whereas no significant differences were observed in AVNRT.

In this cohort, OIC use was associated with higher AAS and lower recurrence, with the favorable association primarily observed in AVRT rather than AVNRT. These findings support further evaluation of substrate-specific catheter selection, particularly for accessory pathway ablation.